PET to monomer via glycolysis reaction
While plastic is an integral and indispensable part of modern life, traditional waste management methods, such as landfilling and incineration, are not sustainable solutions. As the demand for sustainable packaging solutions increases, the use of rPET has become a key focus area for industry. Recycling is overwhelmingly effected by either mechanical or chemical processes. Köksan has patented a chemical recycling process that the company describes as “the most advanced and energy efficient”.
The chemical process method of depolymerisation breaks down plastic polymers into their basic monomeric building blocks that can then be used to create new plastic products or other useful chemicals. This process consists of collection and sorting, cleaning and preprocessing, chemical depolymerisation, purification, and repolymerisation.
Köksan, the Turkish producer of PET resin, sheet, and PE closures, says that its patented chemical process of recycling PET to monomer (BHET) by glycolysis reaction is the most advanced and energy efficient technology.
Depolymerisation can contribute to the circular economy by creating a closed-loop system for plastic production and consumption. Recycling plastic, particularly through advanced methods like depolymerisation, will reduce the carbon footprint associated with plastic production and disposal, says Köksan. It can be reused and repurposed, generating new economic opportunities and revenue streams, creating new jobs in the recycling and re-manufacturing industries, further boosting the economy. Advanced depolymerisation technologies have the potential to make plastic recycling more efficient and cost-effective. As they continue to evolve, the economic viability of plastic recycling can be enhanced, making it progressively a more attractive option for businesses and consumers alike.
Köksan says that its patented process achieves high viscosity and lower than 1 ppm AA level in resin. Without any SSP process, it is the most suitable technology for bottle grade application, according to the company. Its new plant will be the first of its kind for 100% rPET resin for all food grade applications. The process of recycling PET flakes through depolymerisation to BHET and subsequent three-micron microfiltration results in a resin that is comparable to virgin monomer, making it suitable for food-grade applications.
The US$ 40 million investment in Köksan rPET plant is designed to produce up to 100% rPET content PET for food grade, textile grade, film grade and engineering applications. The plant has a capacity of 300 MTD bottle grade and 400 MTD for other grades.
As of June 2024, Köksan has the capacity to produce about 240,000 metric t/a of plastic bottles and recycle 72,000 t of it. The chemical recycling project’s 110,000 t of capacity will bring the total recycling capacity to 182,000 t, which is 75% of its plastic bottle production. The recycled plastic bottles are also, themselves, recyclable. Köksan’s plastic recycling investment is set to generate more than US$ 200 million annually.
